Research in this project builds on extensive evidence that (1) the acquisition of alphabetic reading depends crucially on phoneme awareness; and (2) reading disability is consistently associated with an array of deficits ina the perception, retention, retrieval, analysis, and production of spoken language. Working from the hypothesis that some phonological weakness (es) is responsible for all of these deficits including the difficulties with awareness, we ask how and when basic phonological processes contribute to developmental and individual differences in literacy. In IV.D .1, our goal is to clarify what aspects of phonological function are impaired in persons with reading disability by systematically examining some of the major correlates of reading skill: phonological memory, rapid serial naming, and confrontation naming. For each, we seek more definitive evidence that the basis of the association with reading is phonological, and more precise specification of the nature of th underlying phonological weakness(es). As discussed in Best's Project, sometime during the preschool years the child must make the shift from a gesture-based articulatory phonology to one that supports ready identification and awareness of the segmental units to which alphabetic letters refer. Focusing on the period of development between 4 and 7 years of age, the experiments in iV.D.2 address how it is that fundamental changes in phonological representation, evident in phonetic perception an phonological memory, are tied to advances in awareness and literacy. use of experimental training studies allows us to test the direction of influence between primary and metaphonological change; a naturalistic, longitudinal study provides the opportunity to track development in both areas. The experiments in IV.D.3 focus on the older reader, asking whether the same phonological weaknesses that create obstacles in acquiring phoneme awareness and decoding continue to exert a role in higher level aspects of reading. Problems for investigation include th status of phoneme awareness one skilled reading is achieved (recent evidence suggests that it may decline), and the consequences of phonological deficits for comprehension of spoken and written language, as assessed by on-line measures.